Micro-environmental conditions differentially affect plant emergence and establishment in denuded areas of the Patagonian Monte

BOSCO, TOMÁS; BERTILLER, MÓNICA BEATRIZ; CARRERA, ANALÍA LORENA

Manchester

Conferencia; 6th World Conference on Ecological Restoration. "Towards Resilient Ecosystems"; 2015

Society for Ecological Restoration (SER)

Direct seeding of native plants combined with litter amendments could bea key management tool forrestoration of disturbed arid ecosystems. We analyzed the effect ofabiotic controls on seedlingemergence and establishment of perennial grasses (Poaligularis, Nassella tenuis) and evergreenshrubs (Atriplex lampa, Larrea divaricata, Schinusjohnstonii) in denuded areas induced by anthropicdisturbance in the Patagonian Monte. We sowed seeds of these species inmicrocosms subjected tothe combined effects of UV radiation (near-ambient, am-UV; attenuated UVradiation, att-UV), highand low soil moisture (15-25%, HSM; 5-15%, LSM), and litter cover(without litter, BS; low quality litter,LQL; high quality litter, HQL). During 7 months, we estimated weekly theseedlings emerged(coleoptile or cotiledons visible) and the seedlings established (twotrue leaves expanded) aspercentage of emerged seedlings. Combined effects of the three factorsaffected N. tenuis emergencewith the highest values under HQL and HSM for both UV treatments. P.ligularis emergence washigher under am-UV radiation except for HSM at BS. The establishment of P.ligularis was not affectedby factors while that of N. tenuis was promoted by am-UV. A. lampa emergence was promoted by am-UV in both HQL and LQL while the establishment was enhanced by thecombined effects of am-UVand HSM. L. divaricata did not emergeunder att-UV and LSM in any of the three litter covers whereasS.johnstonii mostly emerged under am-UV and HSM at the three litter covers. Theestablishment ofthe latter species was not affected by factors. We concluded thatabiotic factors exerted a strongercontrol on seedling emergence than on seedling establishment. Moreover,the combination of factorsaffecting emergence varied among species. Management tools focused onmanipulation ofmicroenvironments of seedbeds could promote seedling emergence andestablishment of targetspecies forrestoration of denuded areas.